Nato will seal a decision this week to send four battalions to the Baltic states and Poland, the alliance’s chief said on June 13. The move is Nato’s response to renewed Russian activity in eastern Europe, but the four countries that will host the 4,000 troops suggest more will be needed to deter Moscow.

In a move first signalled by the US media in late April, Nato will approve during a meeting in Brussels starting on June 14, of sending the battalions to Poland, Lithuania, Latvia, and Estonia. The alliance will then give the formal nod to the deployment, as well as other deterrents planned to be stationed in eastern Europe, during the Nato summit in Warsaw in early July.

The four eastern European countries – all of them bordering Russia – consider themselves on the frontline of what they perceive as Moscow’s aggression. They have been pushing for a greater Nato presence in the region since Russia annexed Crimea in March 2014.

“We will agree to deploy by rotation four robust multinational battalions in the Baltic states and in Poland,” Nato’s Secretary General Jens Stoltenberg said in Brussels on June 13. He added the battalions are part of a shift in NATO’s “defence and deterrence posture,” including a larger NATO Response Force, a new Spearhead Force and eight new small headquarters in the eastern part of the alliance.

“All together this strikes the right balance between a greater ability to reinforce, and a boost to our forward presence,” he added.

However, Poland and the Baltic states hinted the deployments will not be enough to deter Russia from considering aggression. “We cannot exclude [aggression] ... They might exercise on the borders and then switch to an invasion in hours,” Lithuanian Defence Minister Juozas Olekas told Reuters.

Alongside his regional peers, Olekas said he will try to convince other Nato states to help build an air defence system, the newswire reports. They are also wary of the strategic potential of Kaliningrad, the Russian exclave that sits to the west of Poland and Lithuania on the coast of the Baltic Sea.

The decision to send the battalions is just the latest in a series of pledges from Nato intended to assure eastern members they will not be left without support. In February, Washington announced a budgetary boost of $3.4bn (€3.11bn) to send extra heavy weapons, armoured vehicles and other equipment to the CEE region. The following month, an additional armoured brigade for the region was detailed.